Kalonzo has been away in Germany tending to his ailing wife
Majority Leader in the National Assembly Aden Duale made the rather surprise announcement ahead of voting which is expected to take place on Thursday afternoon.
Duale stated that Jubilee had resolved to defend Wiper after it was denied a chance to have a nominee in the powerful Parliamentary Service Commission (PSC).
NASA nominated Senator George Khaniri (ANC), Gladys Wanga (ODM) and Aisha Juma, also from the orange party.
"I'm going to defend Wiper because the party leader is away and this afternoon we are going to vote for his son," Duale announced.
Kalonzo's son, Kennedy Musyoka, is among 25 nominees who have been proposed to serve in the Arusha-based regional Assembly.
NASA Leader Raila Odinga's elder brother, Oburu, is also on the list.
Out of the nominees, MPs will vote for nine representatives - five from Jubilee and four from NASA.